Heterogeneity of Expression of CD68 and Other Macrophage-associated Antigens in Human Long-term Bone Marrow Culture

The authors have performed an immunohistochemical study of intact human long-term bone marrow cultures (hLTBMC) grown directly onto glass slides. Between 4 and 12 weeks of growth, such cultures consist of a complex stromal layer supporting foci of haemopoietic cells which undergo granulocytic and monocytic differentiation. As part of a large panel of antibodies employed to characterize monocytes and macrophages within hLTBMC, we included six different anti-CD68 reagents and three antibodies representing a putative new CD group recognizing a macrophage-associated antigen of 130 kDa molecular weight. These gave heterogeneous immunostaining patterns with macrophages and stromal myofibroblastic cells.